DetailsViewUpdateEventArgs.Keys Property
Gets a dictionary that contains the key field name/value pairs for the record to update.
Assembly: System.Web (in System.Web.dll)
Property Value
Type: System.Collections.Specialized.IOrderedDictionaryAn IOrderedDictionary that contains a dictionary of key field name/value pairs for the record to update.
Use the Keys property to access the values of the key fields for the record to update. For example, you can use these values to keep a log of updated records.
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This property contains only the key fields. To access the updated and original non-key fields, use the NewValues and OldValues properties, respectively. |
The Keys property returns an object that implements the IOrderedDictionary interface. The object contains DictionaryEntry objects that represent the fields of the record to update.
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As a shortcut, you can also use the indexer of the IOrderedDictionary object to access the field values directly. |
The following code example demonstrates how to use the Keys property to access the value of the key field for the record being updated.
<%@ Page language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub CustomerDetailsView_ItemUpdating(ByVal sender As Object, _ ByVal e As DetailsViewUpdateEventArgs) ' Validate the field values entered by the user. This ' example determines whether the user left any fields ' empty. Use the NewValues property to access the new ' values entered by the user. Dim emptyFieldList As ArrayList = _ ValidateFields(CType(e.NewValues, IOrderedDictionary)) If emptyFieldList.Count > 0 Then ' The user left some fields empty. Display an error message. ' Use the Keys property to retrieve the key field value. Dim keyValue As String = e.Keys("CustomerID").ToString() MessageLabel.Text = _ "You must enter a value for all fields of record " & _ keyValue & ".<br/>The following fields are missing:<br/><br/>" ' Display the missing fields. Dim value As String For Each value In emptyFieldList ' Use the OldValues property access the original value ' of a field. MessageLabel.Text &= value & " - Original Value = " & _ e.OldValues(value).ToString() & "<br />" Next ' Cancel the update operation. e.Cancel = True Else ' The field values passed validation. Clear the ' error message label. MessageLabel.Text = "" End If End Sub Function ValidateFields(ByVal list As IOrderedDictionary) _ As ArrayList ' Create an ArrayList object to store the ' names of any empty fields. Dim emptyFieldList As New ArrayList() ' Iterate though the field values entered by ' the user and check for an empty field. Empty ' fields contain a null value. Dim entry As DictionaryEntry For Each entry In list If entry.Value Is Nothing Then ' Add the field name to the ArrayList object. emptyFieldList.Add(entry.Key.ToString()) End If Next Return emptyFieldList End Function Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) If e.CancelingEdit Then ' The user canceled the update operation. ' Clear the error message label. MessageLabel.Text = "" End If End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>DetailsViewUpdateEventArgs Example</title> </head> <body> <form id="form1" runat="server"> <h3>DetailsViewUpdateEventArgs Example</h3> <asp:detailsview id="CustomerDetailsView" datasourceid="DetailsViewSource" autogeneraterows="true" autogenerateeditbutton="true" allowpaging="true" datakeynames="CustomerID" onitemupdating="CustomerDetailsView_ItemUpdating" onmodechanging="CustomerDetailsView_ModeChanging" runat="server"> <pagersettings position="Bottom"/> </asp:detailsview> <br/> <asp:label id="MessageLabel" forecolor="Red" runat="server"/> <!-- This example uses Microsoft SQL Server and connects --> <!-- to the Northwind sample database. Use an ASP.NET --> <!-- expression to retrieve the connection string value --> <!-- from the web.config file. --> <asp:sqldatasource id="DetailsViewSource" selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]" updatecommand="Update [Customers] Set [CompanyName]=@CompanyName, [Address]=@Address, [City]=@City, [PostalCode]=@PostalCode, [Country]=@Country Where [CustomerID]=@CustomerID" connectionstring= "<%$ ConnectionStrings:NorthWindConnectionString%>" runat="server"/> </form> </body> </html>
Available since 2.0
